Late Miocene to Pliocene carbon isotope record of differential diet change among East African herbivores
Late Miocene to Pliocene carbon isotope record of differential diet change among East African herbivores
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DOI：
10.1073/pnas.1018435108
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发表时间：
2011-04
期刊：
影响因子：
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通讯作者：
K. Uno;T. Cerling;John M. Harris;Y. Kunimatsu;M. Leakey;M. Nakatsukasa;Hideo Nakaya
中科院分区：
文献类型：
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作者：
K. Uno;T. Cerling;John M. Harris;Y. Kunimatsu;M. Leakey;M. Nakatsukasa;Hideo Nakaya
稳定同位素和分子数据表明，C4禾本科植物在渐新世首次在全球范围内出现。在东非，来自成土碳酸盐和牙釉质化石的稳定同位素数据表明，第一次出现在15-10 Ma之间，随后在上新世-更新世期间扩张。化石釉质记录有可能提供有关不同食草动物谱系对这种新资源的饮食适应率的详细信息。我们目前的碳同位素数据从452化石牙齿，记录饮食变化的差异率从C3到混合C3/C4或C4饮食在东非食草动物家庭在7个不同的时间段晚中新世上新世（9.9-3.2马）。大量的C4草存在于马的饮食开始于9.9马和犀牛的饮食9.6马，虽然没有同位素证据表明，在这一部分的晚中新世的C4草原。牛科动物和科动物在7.4 Ma之前的饮食以C4为主（>65%）的个体也是如此。6.5 ~ 4.2Ma，猪的食性以C4为主。Gomphotheriids和象鼻虫主要是C3占主导地位的饮食，通过9.3马，但成为专门的C4食草动物的6.5马。恐兽和长颈鹿在整个记录中保持了主要的C3饮食。食草动物谱系之间的差异饮食变化的顺序提供了生态学洞察的关键时期的原始人的进化和有价值的信息，为未来的研究，重点是形态变化与饮食变化。
Stable isotope and molecular data suggest that C4 grasses first appeared globally in the Oligocene. In East Africa, stable isotope data from pedogenic carbonate and fossil tooth enamel suggest a first appearance between 15–10 Ma and subsequent expansion during the Plio-Pleistocene. The fossil enamel record has the potential to provide detailed information about the rates of dietary adaptation to this new resource among different herbivore lineages. We present carbon isotope data from 452 fossil teeth that record differential rates of diet change from C3 to mixed C3/C4 or C4 diets among East African herbivore families at seven different time periods during the Late Miocene to the Pliocene (9.9–3.2 Ma). Significant amounts of C4 grasses were present in equid diets beginning at 9.9 Ma and in rhinocerotid diets by 9.6 Ma, although there is no isotopic evidence for expansive C4 grasslands in this part of the Late Miocene. Bovids and hippopotamids followed suit with individuals that had C4-dominated (>65%) diets by 7.4 Ma. Suids adopted C4-dominated diets between 6.5 and 4.2 Ma. Gomphotheriids and elephantids had mostly C3-dominated diets through 9.3 Ma, but became dedicated C4 grazers by 6.5 Ma. Deinotheriids and giraffids maintained a predominantly C3 diet throughout the record. The sequence of differential diet change among herbivore lineages provides ecological insight into a key period of hominid evolution and valuable information for future studies that focus on morphological changes associated with diet change.